Arm for a forklift fork and a forklift fork

ABSTRACT

An arm of a forklift fork including a substantially horizontal arm having a supporting surface for supporting and carrying a load. The arm may include a carriage that also includes a supporting surface for supporting and carrying a load, wherein the carriage is arranged to move in parallel to the arm in relation to the supporting surface of the arm. The carriage may include a caterpillar track for moving. The arm may include two adjacent arm parts fastened to each other, between which parts the carriage is located. The arm may include several separate units, each containing members which make the load capable of rolling in parallel to the arm. Each unit is also arranged to remain in its place.

The invention relates to an arm of a forklift fork. The invention alsorelates to a forklift fork.

According to prior art, various forklifts and reach trucks are used forthe unloading and loading of freight containers with various loads,including various units assembled on pallets, individual products, suchas paper rolls of various types and various bound stacks such as stacksof timber. In reach trucks forklift forks are used as an implement formoving and carrying loads. Forklift forks typically comprise twohorizontal arms located underneath the load.

For example stacks of timber are long and when they are loaded in afreight container, the forks must be pushed underneath the stack fromthe end of the stack. Efficient handling of the stacks requires that thestacks are positioned on top of the fork in a stable manner. There areoften transverse props or supports underneath the stacks, and the forkmust be pushed under them, which makes the handling difficult becausethe stacks are not handled from their sides, in which case it would beeasy to push the forks under the stack between the supports. The pushingof the fork under the stack may damage the supports, the load or thebelts holding the stack together, or the products in the stack,especially in cases where there are no supports and the stack is heavyand long.

It is an aim of the invention to eliminate the problems presented above,relating to the handling of loads. By means of the solution according tothe invention it is possible to handle loads, especially stacks oftimber without damaging them.

The arm of a forklift fork according to the invention is presented inclaim 1. The forklift fork according to the invention is also presentedin claim 8. The arm of a forklift fork according to the invention isalso presented in claim 11.

The solution also has several other advantages. By means of the solutionit is possible to avoid abrasion between the load and the arms of theforklift fork, wherein it is easier to transfer the load on top of theforklift fork because there is less friction. At the same time it ispossible to avoid abrasion that may damage the load.

By means of the solution the load rolls along the arm of the forkliftfork, but the solution is still simple, because it is not necessary toprovide the load with rolls or fasten an idler assembly to the fork ontop of which the load would move. The carriage according to the solutionprovides the load with a supporting point which moves with the load andeasily along the arm of the forklift fork. The carriage does not move inrelation to the load, wherein it is not necessary to construct the lowersurface of the load in such a manner that the load would slide or moveeasily for example on top of an idler assembly. The arm of the forkliftfork is designed in such a manner that the carriage moves easily forexample along a flat surface.

The solution is also simple in that respect that only a carriage whichis significantly shorter than the arm and provides a supporting pointfor the load is required for the arm of the forklift fork. The carriagemoves with respect to the arm of the forklift fork, wherein thesupporting point of the load moves in relation to the arm of theforklift fork and the load can be moved on top of the arm or off thesame. The forklift fork may comprise one or several arms. The carriagesof two or several arms of the forklift fork can be connected with abridge or an interconnector on top of which the load rests. By means ofthe bridge or the interconnector the movement of the carriages issynchronized and the load can be supported better by the forklift fork.

The solution is suitable to be used in forklift trucks or reach trucksand in various independently moving transport and lifting devices, forexample in front loaders.

In another example of the solution there is a group of units in the armof the forklift fork, on top of which units the load can roll. The unitsare stationary and they contain for example a caterpillar track thatsupports the load and by means of which it is easy to push the arm ofthe forklift fork underneath the load or pull the arm from underneaththe load. Preferably, the units are similar to each other and they arefastened or coupled in their places in the arm of the forklift fork. Itis possible to vary the number of the units in accordance with thepurpose of use and on the basis of the size of the arm.

In an embodiment of the solution said unit and said carriage are thesame product, but in the arm there is either one moving unit or severalstationary units. The mounting position of the product varies indifferent embodiments, in other words, it is turned around or upsidedown, depending on that whether the aim is to make the load move inrelation to said product (the unit described above that does not move inrelation to the arm) or not (the carriage described above that moves inrelation to the arm). The product moves along with the load or carriesthe load by means of members located therein.

The structure of the arm of the forklift fork may also be different inthe embodiments described above.

In the following, the solutions according to the invention will bedescribed in more detail with reference to the appended drawings, inwhich:

FIG. 1 shows the arm of a forklift fork according to one solution, seenfrom the side and cut along the line A-A of FIG. 2,

FIG. 2 shows the arm of a forklift fork according to FIG. 1 in a topview,

FIG. 3 shows the arm of a forklift fork according to FIG. 1 in a rearview,

FIG. 4 shows a top view of a forklift fork according to one solution inwhich two arms of a forklift fork according to FIG. 1 are implemented,

FIG. 5 shows the arm of a forklift fork according a second solution,seen from the side and cut along the line A-A of FIG. 6, and

FIG. 6 shows the arm of a forklift fork according to FIG. 5 in a topview.

Reach trucks typically comprise a boom at the end of which the arm 1 ofa forklift fork shown in FIG. 1 can be fastened. At the end of the boomthere is for example a transfer carriage on which the arm is suspendedand fastened with fastening means. The fastening means consist forexample of a claw 4 positioned at the upper end of the vertical part ofthe arm 1, and a fastener 5 positioned at the lower end of the verticalpart of the arm.

There are typically two transfer carriages, wherein a forklift fork withtwo arms is formed, and the transfer carriages can be typically moved aswell, wherein the mutual distance of the arms can be changed for variousloads. Instead of a transfer carriage, the boom may comprise a frame forthe forklift fork or members to which one or several arms are fastenedwith said fastening means, and the arms cannot be moved.

The arm 1 is typically L-shaped, and the load is positioned on itselongated horizontal part. The load is also positioned against thevertical part, which can be provided with a rubber coating, whichbecause of the friction between the load and the rubber keeps especiallya long stack of timber in its place and prevents it from swingingforward, away from the fork. In this specification reference is made tothe operating position of the arm, in which it is substantiallyhorizontal.

In accordance with the solution of FIG. 2, the horizontal part of thearm 1 is provided with a moving carriage 2, capable of moving back andforth in the longitudinal direction of the arm 1. The upper surface ofthe carriage 2 is provided with a supporting surface positioned underthe load and supporting the load.

In the solution according to FIG. 2, the carriage 2 is of such a typethat there are members on the lower surface of the carriage by means ofwhich the carriage 2 is capable to move in a rolling manner along thesupporting surface in the arm 1. Said supporting surface is in theexample of FIG. 2 positioned in a longitudinal trough 3, along which thecarriage moves and for example the edges of the trough 3 restrict themovement of the carriage 2 both in the longitudinal and transversedirection. The carriage 2 can also be arranged to move along the arm 1in other ways, taking advantage of various idler assemblies, rolls orguides. However, in this example a simple and reliable structure hasbeen attained, because the carriage 2 contains members for rolling andonly a supporting surface for the carriage 2 is necessary in the arm 1.Preferably said members comprise a caterpillar track constructedadvantageously of a chain, or for example a belt. The endless belt orchain travels around idler wheels.

Preferably, the carriage 2 is fastened to the arm 1 in a removablemanner. Preferably, when the arm 1 does not contain a carriage 2 it canalso be used as a conventional arm of a forklift fork. The supportingsurface of the arm 1 along which the carriage 2 moves is preferablyseparate with respect to the supporting surface of the arm 1 againstwhich the load is positioned. In use, the supporting surface 1 c of thearm intended for the carriage 2 is in the example of FIG. 2 located on alower level than the supporting surface 1 d of the arm intended for theload. The supporting surface 2 a of the carriage that is intended forthe load is, in turn, positioned on a higher level than the supportingsurface 1 d of the arm. The supporting surfaces are positioned in themanner described above in all positions of the carriage 2 between theend positions B and C of the carriage 2 shown in FIG. 2, and in said endpositions.

The forklift fork is used in such a manner that the carriage 2 islocated for example at the outermost end of the arm 1, for example inthe end position B and the carriage 2 is positioned underneath the load,for example under the end of a stack of timber. The load is raised bymeans of the carriage 2 and at the same time the arm 1 is tilted forwardso that the arm 1 can be pushed further underneath the load. Because theload then remains in its place, the carriage 2 between the arm 1 and theload also remains in its place, but the arm 1 moves in relation to thecarriage 2. The forklift fork is moved until the load is sufficiently ontop of the arm, wherein the carriage 2 is positioned for example in theend position C and the load is positioned against the vertical part ofthe arm 1. Thereafter the arm 1 is tilted backward, so that theoutermost end of the arm 1 is also positioned against the loadunderneath the load, holding the load in its place. Thus, the carriage 2and the load are not capable of moving, because the other parts of thearm hold the load in its place by means of friction and support the loadtogether with the carriage 2. The delivery of the load takes place inopposite order when compared to the aforementioned method.

FIGS. 1 to 3 also show an example of the solution, which utilizestraditional arms of forklift forks. According to FIG. 2, the arm 1comprises two conventional arms of a forklift fork, which form the armparts 1 a and 1 b located next to each other, between which the trough 3and the fastening means 4 and 5 have been mounted. The arm parts 1 a, 1b are also fastened to each other for example by means of bridges orconnecting beams 6 and 7, which are located for example in the verticalpart. The length of the trough 3 nearly corresponds to the length of thearm parts 1 a, 1 b and the horizontal part of the arm 1.

In accordance with FIG. 4, the forklift fork can be formed of two arms 1of the forklift fork according to the solution, the carriages 2 of whichhave been connected by means of a bridge 8. The bridge 8 synchronizesthe movements of the carriages 2 and it makes it possible to form awider supporting surface 2 a for the load. The carriages 2 may also beconnected with a bridge that is not supported underneath the load. Inthe example of FIG. 4, the bridge 8 is positioned on top of thecarriages 2, and it is fastened to the carriages 2 in a removablemanner. There may be several bridges 8 in use, and each of them is beingused for a specific distance between the arms 1. Alternatively, thebridge 8 and at least one carriage 2 are connected to each other so thatthe carriage 2 is capable of moving in parallel to the bridge 8 when thedistance between the arms 1 is changed for example by means of thetransfer carriages of the forklift fork, or the distance between thearms 1 is changed manually.

The members by means of which the carriage 2 is capable of rolling alongthe supporting surface on the arm 1 can also be integrated to the bridge8, wherein the bridge 8 at the same time forms the necessary carriageand the structure connecting the arms 1, providing a combined supportingsurface or several supporting surfaces for the load, corresponding toone or several supporting surfaces 2 a. Said carriage and bridgestructure is thus supported by two or several adjacent arms.

FIG. 5 shows another solution for the arm 1 of the forklift fork. Inaccordance with the solution of FIG. 5, the horizontal part of the arm 1is provided with successive units 8 for supporting the load 9. Each unit8 is separate and remains in its place during use. The load 9 is capableof moving back and forth in the longitudinal direction of the arm 1 ontop of the units 8. The upper surface of the unit 8 is provided with asupporting surface 8 a positioned under the load and supporting theload.

In the solution according to FIG. 5, each unit 8 is of such a type thatthere are members on the upper surface 8 a of the unit by means of whichthe load 9 is capable of rolling along the arm 1 and against the unit 8.Said unit 8 is in the example of FIG. 5 positioned in a longitudinaltrough 3, and for example the edges of the trough 3 keep the units 8 intheir places both in the longitudinal and transverse direction. Theunits 8 can be fastened to the arm 1 in other ways as well. The trough 3may be replaced with a supporting surface of corresponding size, forexample a planar plate. The load 9 can also be arranged to move alongthe unit 8 in other ways, taking advantage of various idler assemblies,rolls or guides. However, in this example a simple and reliablestructure has been attained, because the unit 8 contains members forrolling and only a supporting surface suitable for the units 8 isnecessary in the arm 1. Preferably said members comprise a caterpillartrack constructed advantageously of a chain, or for example a belt. Theendless belt or chain travels around idler wheels. In one example thecaterpillar track is composed of successive rolls connected to eachother and forming an endless loop. The caterpillar track rolls aroundthe unit 8 so that in the supporting surface 8 a the load 9 is supportedby the caterpillar track, which, in turn is supported by the frame ofthe unit, and the rolling rolls move the load 9 at the same time. In thelower surface of the unit 8 the frame of the unit is supported by thearm, for example the supporting surface of the arm. The caterpillartrack moves past the frame and through the same so that the caterpillartrack is not supported by the arm 1, wherein the unit 8 remains in itsplace.

Preferably, the unit 8 is fastened to the arm 1 in a removable manner.Preferably, when the arm 1 does not contain units 8 it can also be usedas a conventional arm of a forklift fork. The supporting surface of thearm 1 to which the units 8 are to be fastened can be separate withrespect to the supporting surface of the arm 1 against which the load ispositioned. In use, the supporting surface 1 c of the arm intended forthe units 8 is in the example of FIG. 5 located on a lower level thanthe supporting surface 1 d of the arm intended for the load. Thesupporting surface 8 a of the unit 8 intended for the load is, in turn,positioned on a higher level than the supporting surface 1 d of the arm.

The forklift fork is used in such a manner that the unit 8 is positionedunder the load. The load is raised by means of the unit 8 and at thesame time the arm 1 is tilted forward so that the arm 1 can be pushedfurther underneath the load and the unit 8 rolls against the loadtogether with the arm 1. The forklift fork is moved until the load issufficiently on top of the arm. Thereafter the arm 1 is tiltedbackwards. There are situations in which the outermost end of the arm 1that does not contain a unit 8 is positioned against the load underneaththe load, holding it in its place. The delivery of the load takes placein opposite order when compared to the aforementioned method.

FIGS. 5 and 6 also show an example of the solution, which utilizestraditional arms of forklift forks. According to FIG. 5, the arm 1comprises two conventional arms of a forklift fork, which form the armparts 1 a and 1 b located next to each other, between which the groove 3or the supporting surface of said units and the fastening means 4 and 5have been mounted. The arm parts 1 a, 1 b are also fastened to eachother for example by means of bridges or connecting beams 6 and 7, whichare located for example in the vertical part. The length of the trough 3or the supporting surface nearly corresponds to the length of the armparts 1 a and 1 b and the horizontal part of the arm 1.

The invention is not limited solely to the examples discussed orpresented above, but it may vary according to the appended claims.

1. An arm of a forklift fork, comprising: a substantially horizontal armcomprising a supporting surface for supporting and carrying a load,wherein the arm further comprises a carriage which also comprises asupporting surface for supporting and carrying a load, wherein saidcarriage is arranged to move in parallel to the arm in relation to thesupporting surface of the arm.
 2. The arm of a forklift fork accordingto claim 1, wherein the supporting surface of the arm is located on alower level than the supporting surface of the carriage.
 3. The arm of aforklift fork according to claim 1, further comprising: a supportingsurface for the carriage, wherein said carriage is arranged to movealong said supporting surface.
 4. The arm of a forklift fork accordingto claim 1, wherein the carriage further comprises a caterpillar trackfor moving.
 5. The arm of a forklift fork according to claim 1, furthercomprising: a trough along which said carriage is arranged to move. 6.The arm of a forklift fork according to claim 1, wherein the arm furthercomprises a horizontal part and a substantially vertical part fastenedthereto, the substantially vertical part comprising a fastenerconfigured to fasten to a forklift truck or a reach truck.
 7. The arm ofa forklift fork according to claim 1, wherein the arm further comprisestwo adjacent arm parts fastened to each other, between which parts saidcarriage is located.
 8. A forklift fork, comprising: two substantiallyhorizontal arms each comprising a supporting surface for supporting andcarrying a load, wherein each arm further comprises a carriage whichalso contains a supporting surface for supporting and carrying a load,wherein said carriage is arranged to move in parallel to the arm inrelation to the supporting surface of the arm.
 9. The forklift forkaccording to claim 8, wherein two or several of said carriages areconnected by a bridge which synchronizes movement of the carriages andin which the supporting surface of the carriage is located.
 10. Theforklift fork according to claim 9, wherein at least one of saidcarriages is connected to the bridge in such a manner that a location ofthe carriage in relation to the bridge can be transferred in parallel tothe bridge, transversely with respect to the arm, wherein the distancebetween the arms can be changed.
 11. An arm of a forklift fork,comprising: a substantially horizontal arm intended for supporting andcarrying a load, wherein the arm comprises a number of separatesuccessive units each comprising a supporting surface for supporting andcarrying a load, and members on the supporting surface which make theload capable of rolling in parallel to the arm wherein said unit is alsoarranged to remain in its place.
 12. The arm of a forklift forkaccording to claim 11, wherein the arm further comprises a supportingsurface for supporting and carrying the load, wherein the supportingsurface of the arm is located on a lower level than the supportingsurfaces of the units.
 13. The arm of a forklift fork according to claim11, further comprising: a supporting surface for the units, wherein saidsupporting surface is arranged to carry several units and to hold themin their places.
 14. The arm of a forklift fork according to claim 11,wherein each unit comprises a caterpillar track for moving the load. 15.The arm of a forklift fork according to claim 11, wherein the armfurther comprises a trough in which said units are placed.
 16. The armof a forklift fork according to claim 11, wherein the arm furthercomprises a horizontal part and a substantially vertical part fastenedthereto, wherein the substantially vertical part comprises a fastenerconfigured to fasten to a forklift truck or a reach truck.
 17. The armof a forklift fork according to claim 11, wherein the arm comprises twoadjacent arm parts fastened to each other, between which parts saidunits are located.
 18. The arm of a forklift fork according to claim 11,wherein said unit which is turned upside down, forms a carriagecomprising a supporting surface for supporting and carrying the load,wherein said carriage is arranged to move in parallel to the arm. 19.The arm of a forklift fork according to claim 18, further comprising: asupporting surface for the units, wherein said supporting surface isarranged to carry several units and to hold them in their places, andsaid carriage is arranged to move along said supporting surface.
 20. Thearm of a forklift fork according to claim 18, wherein each unitcomprises a caterpillar track.